1. Field of the Invention
The present invention relates to an XYZ coordinates measuring system and particularly to an improved high-speed system for measuring the XYZ coordinates on the surface of a work to be measured.
2. Description of the Related Art
On production of machine parts or products, it is frequently required to attain the high-speed dimension measurement of a machine part or product and the high-speed measurement of a distance between the machine part or product and a parts handling device such as measuring device, inspecting device or automatically assembling robot arm.
When a work to be handled is of a three-dimensional configuration, it is particularly desired to perform the high-speed detection of XYZ coordinates on the surface of the work so that the geometrical feature thereof can be accurately grasped.
FIG. 2 shows one of the related art systems for optically measuring the surface configuration of a three-dimensional work 10. The optical measuring system comprises a source of slit light 12 adapted to project a slit light beam 100 onto the surface of the work 10, and a TV camera 14 adapted to take a light line 200 formed on the surface of the work by the slit light 100. Each of the points on the surface of the work is determined with respect to XYZ coordinates by the use of the triangulation technique.
FIG. 3 shows an image 200a of the light line 200 taken by the TV camera 14. It will be apparent from this figure that the respective points (P1, P1, P2 . . . ) at which the light line 200 intersects the respective horizontal scanning lines (y=0, 1, . . . and 479) correspond to XYZ coordinates on the work. For example, if it is assumed that there is used a conventional TV camera 14 including 480 horizontal scanning lines, XYZ coordinate data relating to the maximum number of 480 points will be detected from the image 200a of the light line.
If the slit light source 12 and the TV camera 14 are stationary and when the three-dimensional work 10 is moved at a constant speed in a direction X shown in FIG. 2 by the use of a belt conveyor or the like, the three-dimensional configuration of the entire surface of the work can be measured by scanning it with the light line 200.